Lectures 2-3 Flashcards
What is the Miasma Theory?
A theory that stated that diseases (cholera, plague, etc.) were caused by “bad air” or “night air” as microbes were not identified a species
What bacterium caused the Bubonic Plague?
Bacterium: Yersinia pestis
Why was the Bubonic plague a major epidemic?
It was related to poor sanitation, and spread by fleas and rodents. There was no recognition of the bacterium and no proper treatment
What virus causes Smallpox?
Variola Virus
What bacterium causes Cholera?
Bacterium: Vibrio cholerae
Who “gave birth” to Microbiology and how?
Architect Robert Hooke was the first to “see” and record eukaryotic microbes in the 17th century
What did Antonie van Leeuwenhoek become the first to do?
Became the first to observe single-celled organisms, “Animalcules”, in the 17th century
What is Spontaneous Generation?
The theory that living creatures could arise from nonliving matter.
How was Spontaneous Generation disproven?
Lazzaro Spallanzani, experimenting with showed that nonliving matter failed to grow a “life source’ without being exposed to air
What is Spallanzani’s Process?
First, he boiled meat broth and let it sit without capping it. When he did so, microbes grew within the broth, Then he boiled another flask of meat broth, capped it, and let it sit. No microbes grew in the flask until he uncapped it.
What is Germ Theory?
A theory that some diseases are caused by microorganisms
Who are the major contributors to Germ Theory?
Florence Nightingale, Louis Pasteur, and Joseph Lister
What are Florence Nightingale’s contributions?
Discovered soldiers were dying more of microbial infections than battle wounds in the Crimean War and showed the statistical correlation between sanitation and mortality.
What is Louis Pasteur’s experiment?
He boiled broth and let it sit for a year. No microbes appeared during that time, however they multiplied rapidly once he tipped the flask sideways. He theorized that microbes would settle in the curve of a swan-necked flask, but accumulate if it they were shifted towards the broth in the flask.
What are Joseph Lister’s contributions?
He realized that gangrene (tissue death) and death after surgery was caused by infections. He pioneered antiseptic practices and hygiene before and during surgery (ex. sterilizing instruments, cleaning wounds, wearing gloves, etc.)
What is Robert Koch’s postulates?
1) The microbe should be present in all infected organisms, but not healthy organisms
2) The microbe will be isolated and grown in a pure culture
3) If the microbe is introduced to a healthy organism, it should cause disease
4) The microbe will be reisolated and should be identical to the original microbe.
Who is Edward Jenner and what are his contributions?
Edward Jenner was an English physician and the first to utilize vaccination to control an infectious disease by isolating cowpox pus and injecting it into a child with smallpox after seeing milkmaids were more immune to severe smallpox.
Who discovered archaea and how?
Carl Woese discovered bacteria which not only adapted to extreme life conditions, but also had a distinct lineage. He named the species “Archaea”
Who discovered viruses and how?
1) Dmitri Ivanovsky discovered a disease-causing agent
2) Matinus Beijerinck coined the agent as a “virus” ‘
3) Wendell Stanley purified and crystallized the agent. Using electron microscopy, he identified the agent as the Tobacco Mosaic Virus (TMV).
Who is Sir Alexander Fleming and what are his contributions?
Alexander Fleming discovered the Penicillium notam inhibits the growth of Staphylococcus bacteria (causes skin and tissue infections), effectively discovering antibiotics (penicillin)
Mary Hunt discovered more efficient penicillin strains roughly 20 years later.
What is the issue with antibiotics?
Antibiotics disrupt the microorganisms in the gut microbiome and prevent them from microbial resistance and passing it on
What is the issue with globalization and population density when discussing microbes?
The increase of closer proximity between people will increase both the presence of microbes and the transmission of disease.
How does global warming affect microbes?
Microbes grow often thrive in warmer environments, therefore microbes have a larger range of growth in regions since the planet is warming up to optimal temperatures and are increasing in number.
What are the four concerns regarding infection and disease?
1) Antimicrobial Resistance
2) Climate Change
3) Population Density
4) Changes in susceptibility
What are the differences between eukaryotes and prokaryotes?
1) Eukaryotes have membrane-bound organelles
2) Eukaryotes divide through mitosis/meiosis, prokaryotes divide through binary fission
3) Prokaryotic cell walls are more complex than eukaryotic cell walls
What are the unique features used in creating antibiotics against pathogens in bacteria, fungi, and plants?
Bacteria - Peptidoglycan
Fungi - Chitin
Plants - Cellulose
What is the Endosymbiont Theory and what is the process of it?
A theory to explain the origin of eukaryotic cells from prokaryotic organisms:
1) The cell wall is lost
2) Infoldings of the cell membrane increases the surface area to volume ratio
3) Cytoskeleton (microfilaments and microtubules) are formed
4) Internal membrane with ribosomes forms
5) A precursor of the nucleus is formed through the cell’s DNA being enclosed in regions of the cell membrane
6) Microtubules from the cytoskeleton form the eukaryotic flagellum
7) Enzymes from the early endoplasmic reticulum form lysosomes
8) Mitochondria formed through endosymbiosis with a proteobacterium
9) Endosymbiosis with cyanobacteria leads to the development of chloroplasts
